1. Field of the Invention
The present invention relates to an image reading apparatus for reading an image recorded on an original by optically scanning the original.
2. Description of Related Art
In a conventional serial-scanning-type (light-illumination-type) image reading apparatus (hereinafter also referred to simply as a scanner), a carriage on which a scanner head is mounted is moved back and forth across an original which is intermittently transported by a paper transport device, so that an image recorded on the original is scanned and read by the scanner head. Therefore, a portion of the image reading apparatus where the scanner head performs a scanning and reading operation is protected by a cover so as to prevent the user from accidentally touching the carriage or the original during the scanning operation and to prevent ambient light from entering the scanning portion and hindering the reading operation.
However, the provision of such cover makes it impossible for the user to watch the scanning operation. That is, the user cannot know through a visual observation whether the apparatus is in operation or the operation is complete, and cannot notice an occurrence of an error during the scanning operation. To avoid such an inconvenience, there is provided an LCD (liquid crystal display) panel or a plurality of LEDs (light emitting diodes) for indicating the status of the scanning operation of the apparatus, so that the user can confirm the status of the apparatus with the cover kept covering the scanning and reading portion.
Further, in recent years, a combined-function apparatus in which an image reading function and a printing function are combined has been realized (as disclosed in, for example, Japanese Patent Publications No. Hei 1-20832, No. Hei 2-21711 and No. Hei 2-21712). In such a combined-function apparatus, while a single paper transport system is used in common, either a printing head or a scanner head is mounted on a single carriage in an exchangeable fashion. Therefore, it is desired that the combined-function apparatus have the capability of indicating which of the two types of heads, i.e., the printing head and the scanner head, is mounted on the carriage at present.
Further, in the case of a line-scanning-type (light-illumination-type) image reading apparatus, as shown in FIG. 14, there is used, as illumination means for radiating light onto the surface of an original, a fluorescent lamp 95 having a length sufficiently large to illuminate the original over its entire reading width (width of the original in a direction perpendicular to the paper of FIG. 14). In FIG. 14, reference numeral 94 denotes a condensing lens for condensing the light reflected from the original 50 illuminated by the fluorescent lamp 95 onto an image sensor 93. The image sensor 93 is constructed with a photoelectric conversion element such as a CCD or a photodiode.
However, the provision of such an LCD panel or a plurality of LEDs results in an increase in the number of components, such a substrate, parts of the LED or LCD panel, and thus results in an increase in cost. Although the cost may be reduced by employing a small number of display devices such as LEDs, it is required to indicate information by means of on/off combinations or blinking patterns of the reduced number of LEDs. Such a display method is not easy for users to understand.
Furthermore, the employment of the fluorescent lamp as the illumination means (light source) results in various problems. More specifically, electrodes disposed at both ends of the illumination means do not make any contribution to emission of light. Furthermore, a special power supply for supplying electric power to the fluorescent lamp is required, so that the total size of the light source becomes large, and large electric power is consumed.
It is an object of the present invention to make it possible to indicate the status of an image reading apparatus with a simple structure.
It is another object of the present invention to provide a smaller-sized light source which consumes less electric power.
According to an aspect of the present invention, there is provided an image reading apparatus which comprises a light source for illuminating an original, reading means for reading light from the original illuminated by the light source, and an indication part for indicating an operating status of the apparatus by using illumination light emitted from the light source. This allows the operating status of the image reading apparatus to be indicated using a simple mechanism.
According to another aspect of the present invention, there is provided an image reading apparatus which comprises light radiating means for radiating light simultaneously over an entire width direction of an original, which direction is perpendicular to a direction in which to transport the original, and photoelectric conversion means for photoelectrically converting light reflected from the original illuminated by the light radiating means into an image signal and for outputting the image signal, wherein the light radiating means comprises a plurality of light emitting element groups, each group being composed of three kinds of light emitting elements for emitting light with three primary colors, the plurality of light emitting element groups being arranged along the width direction of the original perpendicular to the direction in which to transport the original, and wherein the light radiating means further comprises an optical waveguide for guiding light emitted from each of the light emitting elements to the original in such a manner that the three kinds of light emitting elements produce the same illumination field on the original. Thus, it becomes possible to realize a small-sized light source which consumes less electric power.
These and other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodiments thereof taken in conjunction with the accompanying drawings.